1. The Field of the Invention.
The present invention relates generally to portable illumination devices, and more particularly, but not entirely, to flashlights with enhanced functionality and reliability.
2. Description of Background Art.
Flashlights and other portable illumination devices are very useful devices that include an illumination source as part of an electrical circuit incorporating one or more batteries (to supply current to the illumination source) and a switch to complete or interrupt the circuit. Typically, manually operated mechanical switches which have been designed for the mechanical sturdiness have been used as flashlight switches, such as the switch disclosed in U.S. Patent No. 4,286,311 (granted Aug.25, 1981 to Maglica), which is hereby incorporated by reference. The function of a switch in previously available flashlight has been limited to completing or interrupting the electrical circuit to the illumination source.
The switch used in the ""311 patent is a push-button switch featuring a rotary contact, which is rotated axially when the button is depressed, xe2x80x9cwipingxe2x80x9d across stationary contacts that complete the circuit with the lamp and the batteries, in order to clean those surfaces. This is done to overcome the problems of oxidation and buildup of dirt on the electrical contacts, occurrences which increase electrical resistance in the circuit and thus undesirably limit the current flow to the illumination source.
As a result, the previously available switches require that the switch be activated with enough force to clean the contacts and rotate, or otherwise move cleaning components. The preciously available flashlights using such switches thus require an amount of force large enough to provide the xe2x80x9cwipingxe2x80x9d effect. A MAGLITE(copyright) flashlight, believed to be a market embodiment of the device represented in the ""311 patent, requires a mass of over 1270 grams to latch the ""311 type-switch closed when the weight was applied to the pushbutton on the flashlight until the switch was triggered. Moreover, the ""311 type-switch had a stroke distance of over 5 mm to the latching position. This large force and long stroke distance may be difficult for a person with small hands to use while grasping the flashlight, or a person with reduced hand strength, as from an arthritic hand condition.
It is commonly accepted in the industry as true that the large amount of force and distance required to operate the switch, and the audible xe2x80x9cclickxe2x80x9d that accompanies its function, may also serve as a way to prevent the switch from being accidentally operated, as inside a backpack, or toolbox.
Additionally, a switch structure like that shown in the ""311 patent provides simply a way for the circuit of the flashlight to open and close, it does not provide a structure by which additional electrically based functions can be easily added to the flashlight.
It is noteworthy that none of the known prior art provides a portable illumination device with a switch that requires very little force to operate, or a short stroke distance to operate, or a switch which combines the features of needing little force to operate or needing a short stroke distance to operate, with the ability to integrate additional electronic functions within the switch structure.
The available art is thus characterized by several disadvantages that are addressed by the present invention. The present invention minimizes, and in some aspects eliminates, the above-mentioned shortcomings and other problems, by utilizing the methods and structural features described herein.
It is therefor an object of the present invention to provide a portable illumination device that is easy to use.
It is another object of the present invention to provide a portable illumination device that requires a small amount of pressure to operate a switch mechanism which turns the device on and off.
It is a further object of the present invention to provide a portable illumination device with a switch which requires little movement of a user""s finger, and requires less movement than the previously available devices, to operate the device between an operational state and an inactive state.
It is an additional object of the present invention to provide a portable illumination source that is capable of multiple functions, which are controlled by a single switch.
It is a further object of the present invention, in accordance with one aspect thereof, to provide a flashlight which can include multiple functions actuated by a single switch.
It is another object of the present invention to provide a portable illumination device with increased reliability.
It is an additional object of the invention, in accordance with one aspect thereof, to provide a metal flashlight which has an electrically resistive coating provided on the flashlight for improved appearance or protection with the flashlight also including structures to improve electrical conductivity through the flashlight.
The above-recited objects, and other objects not specifically recited, are realized in a specific illustrative embodiment of a flashlight and flashlight electrical connectors as described herein. The flashlight described herein includes a subminiature pushbutton switch that requires a small amount of pressure and a short stroke distance to operate between an open mode (electrically non-conductive) and a closed mode (electrically conductive).
The switch is preferably attached to a member on which an electrical connective structure is disposed. This preferred structure can be carried out by attaching the switch to a printed circuit board. Electrically conductive springs are also preferably attached to the member, so as to make electrically conductive contact with the electrically connective structure.
The member and the switch are preferably protected by a housing, such that the compressive force of the springs (preferably a first spring and second spring) is absorbed and resisted by the housing. In one preferred embodiment of the invention, one spring makes electrically conductive contact with an illumination source, such as an incandescent lamp, or the electrically conductive structures leading to the lamp. The second spring makes electrically conductive contact with a battery, or a electrically conductive structure leading to a battery. A conductive strip is preferably provided to complete the electrical circuit.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by the practice of the invention without undue experimentation. The objects and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims.